Piston-packing



(No Model.)

.F. D. CHILD. PISTON PACKING.

No. 424,856. Patented Apr. 1.1890.

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FRANKLIN D. CHILD, OF NE\VTON, llJlASSAClIUSETTS.

PISTON-PACKING.

SPECIFICATION forming part of Letters Patent No. 424,856, dated April 1, 1890.

Application filed May 28, 1889. Renewed March 8, 1890. Serial No. 343,179. (No model.)

To all whom it may concern:

Be it known that I, FRANKLIN D. CHILD, of Newton,in the county of Middlesex and State of Massachusetts, have invented a new and useful Improvement in Piston-Packings, of which the following, taken in connection with the accoi'npanying drawings, is a specification.

My invention relates to the construction of packing-rings of pistons for steam-cylinders and other purposes; and it consists in certain novel features of construct-ion, arrangement, and combination of parts, which will be readily understood by reference to the description of the drawings and to the claims to be hereinafter given, and in which my invention is clearly pointed out.

Fignrel of the drawings is a sectional ele- Vation of a piston, illustrating my invention. Fig. 2 is a section on line 00 00 on Fig. 1. Fig. 3 is an inside elevation of a short section of the packing-ring on each side of the separating-cut and of the locking-bar. Fig. 4 is a side elevation of the lockingbar. Fig. 5 is a sectional elevation of a portion of the packingring 011 each side of the line of separation, the cutting-plane being 011 line y 1 on Fig. 3, with the lockingdoar removed. Figs. 6 and 7 are respectively an elevation and a section of aportion of the ring on each side of the line of separation, and illustrating a modification of my invention. Figs. 8 and 9 are respectively an elevation and atransverse section of the lockingdoar of the modified form, and Fig. 10 is an edge view of the modified form of the portions of the packing contiguous to the line of separation.

In the drawings, A is the main body of the piston. B is the follower; O, the piston-rod3 D, the packingring; E, the locking-bar, and a a are springs for forcing the packing-ring D outward.

The usual way of making and fitting packing-rings for steanrpistons is to turn the ring to the desired width and thickness and to a diameter somewhat-sayone-fourth of an inch more or less-greater than the interior of the cylinder in which it is to be used, and cut out a piece of suflicient length circumferentially to permit it to be sprung together, so as to reduce its diameter to the diameter of the cylinder in which it is to work. The spring of the ring itself and the tension of the springs a to tend to press the ring into close contact with theinner surface of the cylinder.

The space between the packing-ringand the body of the piston is usually filled with steam,which also acts to press the packingring outward. This pressure of steam is often so great as to cause an unnecessary wear of the packing-ring and also of the cylinder, thereby necessitating the renewal of the packing-ring in a much shorter time than is desirable. To obviate this objection is the objeet of my present invention, and to this end after turning the ring and cutting it apart precisely as above described I cut through said ring upon each side of the line of separation an open slot F, comprising a narrow parallel-sided central section Z), a wider parallel-sided section 0, and a segmental enlargement (Z contiguous to the line of separation, as shown in Figs. 3 and 5. The ends of the slots F farthest from the line of separation of said ring are radial to the axis of said ring, and the Widest sections 0 of said slots are longer at the outer surface of said ring than at its inner surface, so as to form at the j unction of said wider section 0 with the narrow section 2), two shoulders e c, inclined to the inner and outer surface of said ring, as shown in Fig. 5. I also provide a locking-bar E, provided with inclined shoulders g g and a central hub h, in which is formed a cylindrical recess or cavity i to receive one end of the spring j, the other end of which rests against the spring a and is held in place by the pin it, as shown in Fig. 1. The locking-bar E is made to nicely fit the slots F when the ring D is compressed to fit the diameter of the cylinder, and said bar is placed in position with its curved outer surface in contact with the inner periphery of the cylinder or coinciding with the peripheral curve of the ring D, as shown in Fig. 1. The follower B is firmly secured to the main body of the piston by the bolts Z Z in a well-known manner and the springs a a are arranged and operate in a well-known manner. The two ends of the packing'ring when sprung into position to fit the cylinder in which it is to operate, are locked together by the locking-bar E, which, when inserted in the cylinder, prevents the packing-ring being expanded to an injurious extent by the reaction of its own elasticity, the pressure of the springs a a, or of any steam which may find its way inside of said ring, for the reason that the contact of the shoulders e e on the ring with shoulders g g on the locking-bar prevents further expansion until the outer or curved surface of the lockingbar wears away, so as to be forced farther away from the center of the piston by the spring j or the pressure of steam between it and the body of the piston.

Instead of cutting the slot F through the two ends of the packing-ring, as above described, portions of each end of the ring may be cut away from each edge, as shown in Fig. 6, and-the locking-bar may be made double, as shown in Figs. 8 and 9, without affecting the principles of my invention, as the operation of and the function performed by the locking-bar is precisely the same in both cases.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. A cut packing-ring provided with shoulders on each side of its joint inclined to the inner and outer surfaces of said ring, with their outer ends nearest to said line of separation, and a device for bridging or breaking said joint and provided with correspondinglyinclined shoulders to engage the shoulders on the ring and lock the two ends of the ring together and control the degree of expansion thereof.

2. In combination with the body of a piston, a cut packing-ring having an open slot cut through it at each side of the line of separation and provided with shoulders upon each side of said line inclined to the inner and outer surfaces of said ring, with their outer ends nearest to said line of separation, and a locking-bar to bridge the joint in said ring and provided with correspondingly-inclined shoulders to engage with the shoulders on the ring, substantially as described.

3. In combination with the body of a piston, the ring D," provided with the inclined shoulders e e on each side of the joint thereof, the locking-bar E, provided with the shoulders g g and the recess 2', and the springj, all constructed, arranged, and operating substantially as and for the purposes described.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this 18th day of May, A. D. 1889.

FRANKLIN D. CHILD. WVitnesses:

N. O. LOMBARD, WALTER E. LOMBARD. 

